Brake Booster Issue
 

Hey all,

Hoping to get some input on some repairs the dealer suggested. I brought the car in due issues with brake boost (my petal was stiff and I could hear hissing). From my research, it could be the booster itself failed (rare), a leak in a hose or the check valve.

The suggested repairs to ‘possibly’ fix are $6000 But it’s based on the assumption that the wrong fluid is in my brake system - when they checked the fluid it was a green substance. They concluded the wrong fluid was added, but from what I have read, the fluid can turn green if the ph is off or exposed to moisture.

Here are the notes from the diagnosis. Any advice (I.e. get a second opinion, Could it be something else?) would be greatly appreciated Thanks!

2010 Audi Q5 3.2

https://cimg0.ibsrv.net/gimg/www.aud...daeceb1b8.jpeg

Angela - would you please tell me what the resolution was for this issue.

I suspect I am having a Brake booster / Vacuum issue with my 2006 A4 Quattro 2L. After an overnight park, the pedal effort is high and the pedal is very hard to push with little braking effect. No fluid loss and I recently flushed the brake fluid (after replacing rubber rear brake lines, cracked), with OEM Audi brake fluid about a month earlier.

Same issue, and I recently had the Intake manifold off and may well have a vacuum leak, the issue arose more or less immediately after that work and I have left & right codes for inadequate supplemental air injection flow. Those codes popped about the same time I noticed the brake problem.
What confuses me is that I didn't believe, and don't see any vacuum related dependency as regards the brakes in this or other ABS cars?
Any help??

I have this issue with my 19 SQ5. When I park the car for couple of hours, most times when I open the door, I hear a hissing/hydraulic type of sound. When I go in and push the brake pedal, it is very stiff until I start the car.

Anyone have a suggestion or Experience with this "stiff pedal at low speeds"?
In my case, I had very recently had the intake manifold out to replace the T'Stat. and so may well have created a vacuum leak. It did generate codes for insufficient supplemental air injection, but that could be coincidental.
But I can't see any relationship between vacuum pressure levels and the ABS system. Can anyone enlighten me on this?? Or any other related experiences.
Thanks.

I always thought that this is normal until I turn on the car